Adjustable cylinder for duplicating machines



March 1, 195 H. F. BRUNS' 2,826,142

ADJUSTABLE CYLINDER FOR- DFJPLICATING MACHINES Filed Nov. 20, 1953 I 3Sheets-Sheet 1 INVENTOR 1 /5/25 452T F Bea v:

ATTORNEY March .11, 1958 H. F. BRUNS 2,826,142

ADJUSTABLE CYLINDER FOR DUPLICATING MACHINES Filed Nov. 20, 1953 3Sheets-Sheet 2 INVENTOR M525 1552 rifled/vs.

March 11,1958 H. F. BRUNS 2,826,142.

ADJUSTABLE CYLINDER FOR DUPLICATING MACHINES Filed Nov. 20. 1953 3Sheets-Sheet 3 W62 LE JC NJ' ATTORNEY United States Patent F ADJUSTABLECYLINDER FOR DUPLICATING MACHINES Herbert F. Bruns, Chicago, 111.,assignor to Ditto, Incorporated, Chicago, 111., a corporation of WestVirginia Application November 20, 1953, Serial No. 393,383

6 Claims. (Cl. 101-142) This invention relates to an offset duplicatingmachine and constitutes a continuation-in-part of co-pendingapplications, Serial No. 712,538, filed November 27, 1946 (now PatentNumber 2,660,113, issued November 24, 1953) and Serial No. 154,009,filed April 5, 1950 (now Patent No. 2,753,795), and in particularrelates to spaced members which constitute a cylinder having plate andimpression surfaces, respectively, engageable with a blanket roll foroffset lithographic printing.

It is an object of this invention to provide a cylinder for aduplicating machine, the plate and impression surfaces of such cylinderbeing relatively adjustable to each other.

It is another object of this invention to provide a cylinder constitutedby spaced members which at any position of adjustment relative to eachother, maintain a fixed driving relation between one of such members andthe blanket roll.

The invention is concerned with an offset duplicating machine having arotatable blanket roll engageable with plate and impression surfacesrespectively provided on spaced members which are mounted for rotationabout a common axis disposed parallel to the axis of the blanket roll,such plate and impression surfaces being concentric to the axis ofrotation of the spaced members characterized in that such spaced membersare interconnected by a mechanism which is readily operable to angularlyadjust the members relative to each other and which positively andconstantly maintains the members in controlled spaced relation.

Referring now to the accompanying drawings, wherein;

Figure 1 is a side view, in section, of a portion of a duplicatingmachine including a blanket roll and a cylinder having plate andimpression surfaces;

Figure 2 is a vertical section through the machine, showing the cylinderand the drive shaft therefor in elevation;

Figure 3 is a section and elevation, taken substantially on line 33 ofFigure 2;

Figure 4 is a section and elevation taken on line 4-4 of Figure 2;

Figure 5 is a sectional detail, on the line 5-5 of Figure 3, showing oneof the ring cams, for controlling the ink form roll and the moistureform roll, fixedly secured to the impression sector of the cylinder; andt Figure 6 is a sectional detail, taken on line 66 of Figure 3, showingthe connection of the cylinder driving gear to the plate sector of thecylinder.

Referring to Figures 1 through 6, cylinder 1 comprises a plate holdingmember and a paper holding or impression member. The plate memberconsists in a cylindrical sector 2 having an accurately machinedperipheral sur faces 3 (Figures 3 and 4) and integral inwardly extendingflanges 4 and 5, provided with arcuate, outwardly extending hubs 6 attheir inner ends, and outwardly pro jecting, stepped bosses 7 on theirouter faces. The impression member similarly comprises a cylindricalsector 8 having an accurately machined peripheral surface 9 and "ice endflanges 10 and 11, terminating at their inner ends in arcuate outwardlyextending hubs 12. Stepped bosses 13 also project outwardly from theseend flanges. The hubs 6 and 12 of the sectors 2 and 8 are seated uponthe cylinder supporting shaft 14. Arcuate clamping members 15 and 16embrace the hubs 6 and 12, respectively, at both ends of the cylinder,and are held in clamping relation by bolts 17 extending through a radialbore on each hub 12, through a diametric bore near each end of shaft 14and through a circumferentially elongated slot 18 in each hub 6, so thatthe plate sector 2 may be angularly adjusted relative to the shaft 14and the impression sector 8, while the angular relation between theshaft and the impression sector 8 remains fixed. The adjustment of theplate sector 2 may be effected by a manually adjustable member, such .asturnbuckle rod 19, having a peripherally notched adjusting wheel 20secured to its central portion and having right and left hand threadedends, disposed in correspondingly threaded sleeves 21 and 22 pivotallysecured upon pins 23 and 24 carried by lugs on the respective sectors. Aspring detent 25 appropriately secured to threaded sleeve 22 bearsagainst the notched circumference of the hand wheel to hold the same inadjusted position. A pair of strong resilient members, such as tensionsprings 26, are connected to pins carried by the respective sectors andtend to draw the sectors together against the turnbuckle. By suchconstruction, the adjusting wheel 20 is accessible through the gapbetween the adjacent ends of the sectors 2 and 8.

As an alternative, if desired, the springs 26 may be eliminated and theadjustment and the maintenance of the adjusted spaced condition may behad by use of the turnbuckle rod 19 alone. It is preferred to employ thesprings 26 to overcome any backlash which may be inherent in the loosefit between the threads on the rod 19 and the threads in thecorresponding sleeves 21 and 22.

Secured to the left hand end flange 5 of the plate sector, by cap screws27 extending through spacer sleeves 28 into the bosses 7, is a ring gear29, as shown in Figures 2, 3 and 6. The ring gear 29 is provided withthree cut-out portions 30, bringing the bosses 13 on the left hand endflange 11 of the impression sector 8. Hence, the ring gear29 is boltedto and carried by the plate member, exclusively. The ring gear 29 is inmesh with a gear 31, fast on a drive shaft 32 journalled in the sideframes 33 and 34 and having on its outer end a variable speed drivepulley 35.

The bosses 13, integral with the left hand end flange 11 of theimpression sector 8, serve as seats to support a left hand ring cam 38(Figure 2). The cam is secured in position by cap screws 39, disposed inthe cut-out portion 30 of the ring gear 29, as shown in Figures 3 and 5.

The bosses 13 integral with the end flange 10 at the right hand end ofthe impression sector 8 (Figure 2) serve as seats for a ring cam 40. Thecam 40 is held in place upon the bosses 13 by cap screws 41.

Thus, the ring cams 38 and 40 are fixed with respect to, and are carriedby the impression sector 8 exclusively. The ring cams 38 and 40 engagethe cam following wheels on a moisture form roll 42 and on an ink formroll 43 and move them outwardly to clear the impression sector 8, andpermit such rolls to move inwardly, into a position to make contact withthe printing plate on the plate sector 2.

' The radial dimensions of the plate and impression sectors comprisingthe cylinder are quite critical and are accurately predetermined. Theyhave been selected as a result of giving primary consideration to theplate and paper thicknesses which would most usually be employed. The.aim is to have the plate sector, with a printing plate in positionthereon, of the same overall diameter as the impression sector, with apaper sheet thereon. In other words, the overall diameter of thecylinder as a whole, with the printing plate and paper thereon should bethe same as nearly as possible. It has been found that printlng platesof .006 thickness are the most practical, from the standpoint ofeconomy, flexibility, ease of typing, minimum embossing and durability.It has also been found that 16 lb. and 20 lb. paper stock representsbetween 90% and 95% of the material usually printed with a machine ofthis type. Printing plate thicknesses can be standardized withoutdifficulty, but it is desirable to be able to run all weights of paperranging from tissue to card stock, having thickness variations from.002" to .001". With such variations in paper thickness, it is obviouslyimpossible to maintain the overall radii of the plate and impressionsectors equal, without the use of shims, which are impractical in smallduplicating machines. The paper most commonly used is approximately .004inch thick. Accordingly, the radius of the impression segment is made.002 inch greater than that of the plate sector.

Important advantages result from having the ring gear 29 secured only tothe plate sector 2 and the cams 40, 38 secured only to the impressionsector 8, and from having the plate sector 2 mounted for adjustmentrelative to the supporting shaft 14. As explained below, the blanketroll 45 carries a gear 46 which is continuously in mesh with the ringgear 29. Hence, when the plate and impression sectors are adjustedrelative to each other by the adjusting wheel 20, the plate sector 2 andthe blanket roll 45 do not have relative movement, but the impressionsector 8 and the blanket roll 45 do have relative angular movement. Inother words, the plate sector and the impression sector are relativelyadjustable one to the other while maintaining a fixed driving relationbetween the plate sector and the blanket roll. As a result, the platesector 2 and blanket roll 45 may be adjusted rela tive to the impressionsector 8 and the cylinder shaft 14, to raise or lower the position ofthe image transferred to the paper by the blanket roll, but thisadjustment does not change the position on the blanket roll to which thelmage is transferred by the printing plate. Hence, the formation ofdouble images, on the blanket roll, after adustment, is eliminated, andthe cleaning of the blanket roll between adjustments is unnecessary.

As shown in Figure 1, the blanket roll has a discontinuous surfacewhich, together with the fixed driving relationship between the blanketroll 45 and the plate sector 2, provides a further important advantagein the operation of the machine. Normally, a smear or blob of ink willaccumulate at the leading edge of the printing plate on the plate sector2. If a continuous blanket roll were to be used, this blob of ink wouldbe transferred to the blanket roll. Hence, if the impression sector 8were to be adjusted angularly relative to the plate sector 2, such smearof ink on the blanket roll would be transferred to the sheet beingprinted. The only manner in which such transfer of ink can beeliminated, when using a continuous surface blanket roll, is to cleanthe blanket roll after each adjustment of the sectors 2 and 8. However,by using a discontinuous surface blanket roll, such as 45, and bysetting the blanket roll to initially contact the plate sector, duringrotation, at a line spaced from the leading edge of the plate, the saidsmear of ink on the leading edge of the printing plate will beaccommodated, without contacting the blanket roll, in the gap providedin the surface of the blanket roll. Since the angular position of theblanket roll relative to the plate sector is fixed, an adjustment of theimpression sector relative to the plate sector will not cause a transferof the blob of ink from the plate sector leading edge to the blanketroll. In this fashion positioning the image in different locations onthe paper sheet or the use of diiferent size sheets can readily beeffected and the necessity of I cleaning the blanket roll after eachadjustment is eliminated.

The throw out cams 38 and 40 for the ink and moisture form rolls 42, 43are mounted on the impression sector 8 for the reason that theirfunction is to move the rolls out of contact before they can engage theimpression sector and to drop them back in at the trailing end of theimpression sector so that they are in position to engage the plate onthe plate sector 2.

The leading and trailing end faces of the plate sector 2 carry clamps 47for the corresponding ends of the printing plate, but since these clampsmay be constructed in accordance with the disclosure of Patent No.2,586,146 issued February 19, 1952, they will not be described herein.

From the foregoing description, it will be noted that the inventionprovides a cylinder having plate and impression surfaces which areeasily adjustable relative to each other. Such ease of adjustment ispermitted by the adjustment mechanism, which as shown herein comprisesthe turnbuckle rod 19 but which, without departing from the scope of theinvention, could readily be substituted by a hydraulic cylinder or otherequivalent mechanism. The adjustment mechanism of this inventionpositively maintains the sectors 2 and 8 in controlled spaced relationto each other and which, without necessitating removal of bolts or otherfastening devices, permits the sectors to be readily adjusted angularlyrelative to each other, while at all times maintaining a fixed drivingrelation, by means of gears 29 and 46, between the plate sector 2 andthe blanket roll 45.

In the drawings and specification, there has been set forth a preferredembodiment of the invention, and al though specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation. Changes in form and in the proportion of parts,as well as the substitution of equivalents are contemplated, ascircumstances may suggest or render expedient, without departing fromthe spirit or scope of this invention as further defined in thefollowing claims:

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, what I claimis:

1. A duplicating machine comprising a drive shaft having a gear thereon,a main cylinder including plate and impression segments having theiradjacent ends spaced apart, one of said segments being mounted forangular adjustment relative to the other of said segments so as topermit upper and lower margin adjustments in the printed copy asdesired, adjustable positioning means disposed between adjacent ends ofsaid segments adapted to secure the adjustable segment in a selectedposition of angular adjustment relative to the other of said segments,an ink form roll mounted for movement toward and from the main cylinderfor applying ink to a plate on the plate segment, cam means carriedexclusively in fixed relation by the impression segment for moving theform roll out of contact therewith, a ring gear concentric with the axisof said cylinder carried exclusively by, and in fixed relation to theplate segment, said ring gear being disposed in mesh with the gear onsaid shaft for rotating the cylinder, and a blanket cylinder mounted forrotation adjacent the main cylinder and having a gear mounted thereon,adapted to mesh with said ring gear so that the angular adjustmentbetween said plate segment and said blanket cylinder is constantirrespective of variations in the angular adjustment of said segments.

2. A duplicating machine comprising a main drive shaft having a gearthereon, a main cylinder including plate and impression segments havingtheir adjacent ends spaced apart, and an ink form roll mounted formovement toward and away from the main cylinder, the main cylindercomprising a shaft journalled for rotation on an axis fixed with respectto the drive shaft, means securing the impression segment to the shaftin fixed angular relation, means securing the plate segment to the shaftfor angular adjustment, adjustable positioning means disposed betweenadjacent ends of said segments adapted to secure said plate segment in aposition of angular adjustment relative to said impression segment so asto permit upper and lower margin adjustments in the printed copy, asdesired, cam means fixed with respect to and carried exclusively by theimpression segment for moving the form roll out of contact therewith, aring gear concentric with the axis of said cylinder fixed with respectto and carried exclusively by the plate segment, meshing with the gearon the drive shaft and serving to rotate the cylinder, a blanketcylinder mounted for rotation adjacent the main cylinder and a gearmounted on said blanket cylinder concentric with the axis thereofadapted to mesh with said ring gear so that the angular adjustmentbetween said plate segment and said blanket cylinder is constantirrespective of variations in the angular adjustment of said segments.

3. A duplicating machine comprising a main drive shaft having a gearthereon, a main cylinder including plate and impression segments havingtheir adjacent ends spaced apart, an ink form roll mounted for movementtoward and away from the main cylinder, a blanket cylinder mounted forrotation adjacent the main cylinder, a gear mounted on said blanketcylinder concentric with the axis thereof, the main cylinder comprisinga shaft journalled for rotation on an axis fixed with respect to thedrive shaft, means securing the impression segment to the shaft in fixedangular relation, means securing the plate segment to the shaft forangular adjustment, adjustable positioning means disposed betweenadjacent ends of said segments adapted to secure said plate segment in aselected position of angular adjustment relative to said impressionsegment so as to permit upper and lower mar gin adjustments in theprinted copy, as desired, cam means fixed with respect to and carriedexclusively by the impression segment for moving the form roll out ofcontact therewith, and a ring gear fixed with respect to and carriedexclusively by the plate segment, meshing with the gear on the driveshaft and serving to rotate the cylinder, said ring gear being in meshwith the gear on the blanket cylinder, so that the angular adjustmentbetween said plate segments and said blanket cylinder is constantirrespective of variations in the angular adjustment of said platesegment relative to said impression segment.

4. Apparatus in accordance with claim 1 in which said adjustablepositioning means comprises resilient means interposed between thesegments ur ing them in opposite directions relative to each other andin which a turnbuck e is utilized to select the position of angularadjustment of said adjustable segment.

5. x'trl o fset duplicating machine having a rotatable blanket rollengageable with plate and impression surfaces respectively provided ontwo spaced cylindrical sec tors mounted upon a common shaft, saidimpression sector being secured to said shaft in fixed angular relationthereto, said plate sector being secured to said shaft for an ularadjustment, said shaft mounted for rotation about an axis disposedparallel to the axis of the blanket roll, said plate and impressionsurfaces being concentric to the axis of rotation of the spaced sectors,said plate sector carrying a gear which is in driving engagement with agear carried by the blanket roll for maintaining a fixed drivingrelation between said plate sector and said blanket roll, characterizedin that said spaced sectors are interconnected by a mechanism forangularly adjusting said sectors relative to each other and whichpositively and constantly maintains said sectors in controlled spacerelation including resilient elements which urge said spaced sectors inone direction relative to each other, and an adjustable element whichopposes the direction of thrust of said resilient elements.

6. Machine according to claim 5 characterized in that said adjustablemechanism comprises a turnbuckle which interconnects the spaced sectorsand which has a manually operable adjusting wheel accessible through thespace between said sectors.

References Cited in the file of this patent UNITED STATES PATENTS

